MASSACHUSETTS APPLE INDUSTRY. 27 



Always one must prevent the development of equal forks. By this 

 is meant forks of two or more branches of approximately equal size. 

 Such unfortunate conditions are frequently found where a young tree is 

 cut back at planting and the several branches that arise from the shortened 

 trunk are allowed to develop equally. Sooner or later one or more of 

 these branches splits off with a load of fruit, seriously damaging the 

 tree. This condition is prevented if the side branches are kept subordin- 

 ate to the leader by pruning or perhaps removing some of them. Similarly 

 one must deal with equal forks wherever they appear in the tree. One 

 branch should be cut back severely or entirely removed, and the earlier 

 it is done the better. 



EFFECT OF THE STOCK ON THE SCION 



By J. S. BAILEY 



The variability of seedling root stocks for the apple and the desirabilit.y 

 of having trees propagated on vigorous roots have been recognized for 

 years. But not until recently has experimental work been started to 

 seek out desirable root stocks and practical methods of propagating them. 



This is a report of progress of work being done at the Massachusetts 

 Agricultural Experiment Station to ascertain the effect of several stocks 

 on various scions and to find a hardj, vigorous, uniform stock suitable 

 to be used in the propagation of our common commercial varieties. 



To show the extreme variability in yield of apple trees propagated on 

 seedling stocks, the following data have been taken from reports of the 

 Pennsylvania and West Virginia Experiment Stations. Table 1 gives the 

 total yield in bushels from 1908-1918 of individual trees in a York orchard 

 planted in 1888 in Pennsylvania. The orchard was in sod and the trees 

 whose yields are included in the table were all treated alike and had no 

 fertilizer. The arrangement of the figures in the table corresponds to the 

 location of the trees in tlie orchard. 



7 bu. 



35 ])u. 



17 



Some Grimes trees in a West Virginia orchard show even more striking 

 contrasts. Of two trees growing side by side and getting exactly the 

 same treatment, one yielded a total of 36 bushels and the other 8 pounds 

 for a ten-year period. Still another pair yielded 38 bushels and 2 bushels 

 for the ten-year period. 



The Maine Exi^eriment Station has concluded from data collected over 

 a long period of years that in any one year 3.5 per cent of the variation 

 in yield is due to seedling stocks and 65 per cent to soil differences. 



With the object of eliminating the 35 per cent of variation due to 

 seedling stocks, the Massachusetts Experiment Station started in 1912 

 an experiment to grow a number of varieties on known roots. That is, 

 trees were started on seedling roots and after roots had been sent out from 

 the scion, the seedling roots were cut off. These scion rooted trees were 

 then used as the stocks in this experiment. 



After the stocks had been obtained the orchard now known as the 

 Root and Scion Orchard was planted in 1915. This orchard consists of 

 over 1100 trees. The main part of the orchard, 685 trees, consists of the 

 following top and root varieties: 



